Combine the whole wheat flour, 3/4 cup all-purpose flour, 3/4 teaspoon cinnamon, salt, nutmeg, baking soda, baking powder and dates. Make a well in the center and pour in the egg mixture. Stir until the dry ingredients are just moistened. Fold in the grated zucchini.

Line microwave-safe cupcake pans with paper liners. Half fill each with the batter.

Combine the remaining 3 tablespoons flour with the rolled oats, the remaining brown sugar, walnuts and the remaining 1/4 teaspoon cinnamon. Cut in the butter until the mixture is crumbly. Top each muffin with 1 tablespoon of the crumb mixture.

Microwave 6 muffins at a time on Medium (50 percent) for 4 minutes, rotating the pan a half turn after 2 minutes. Remove the muffins from the pans. Repeat the cooking procedure with the remaining batter. Serve the muffins while they are still warm.